Magnetic tape data storage devices, or tape drives, have long been used for storing large quantities of computer data. More recently, as disc drives have become increasingly faster, tape drives have become more popular for long term data storage and backup. In the forward mode, tape is moved from a supply reel, which supplies the tape, to a take-up reel, which draws tape from the supply reel along a tape path and over the magnetic read/write head. In the reverse mode, tape is moved from the take-up reel to the supply reel.
FIG. 1 schematically illustrates a tape drive 100. The drive 100 accepts a cartridge 102 which has a single reel of tape, generally the supply reel, in the cartridge 102 or magazine. This type of cartridge 102 is used with a tape drive 100 having a take-up reel 104 permanently housed in the tape drive 100. When the tape cartridge 102 is installed in the driving apparatus, a magnetic tape 106 is pulled out of the tape cartridge 102, connected to a leader 110 at connector 108, and is wound by the take-up reel 104 to travel past a head and guide assembly (HGA) 112. The HGA 112 may be used to guide the tape 106 to the take-up reel 104 and back to the cartridge 102. The HGA 112, which reads from and writes to the tape 106, is located along the tape path, and the take-up reel 104 serves to draw the tape across the magnetic read/write head.
The storage and recovery of data from a tape drive is accomplished by head elements in a read/write head. The data is stored in the form of magnetic flux reversals within the magnetic coating on the tape. To maximize flux reversal sharpness, and therefore maximize the amplitude of the data pulses read and written, the head elements are vertically aligned as accurately as possible with the tape as it moves laterally past the elements.
FIG. 2 illustrates the head and guide assembly. The head and guide assembly 112 includes a head 202, and head elements 204 are mounted on the head 202. The faces of the head 202 and head elements 204 together form a substantially continuous surface to contact the leader and the tape. The leader 110 is in direct contact with the head 202 and head elements 204 both during loading (direction of arrow A) and unloading (direction of arrow B) of the tape 106. However, we have found that the leader 110 can drag particles 204a, 204b, 204n (where n is an integer) across the head elements 204 and cause scratching or gouges. These scratches or gouges can degrade the transfer of data between the head elements 204 and the tape 106.